52 INTRODUCTION. 



the Whale : in the one case the skull rests upon the vertebral column, 

 in the other it projects in a straight line from it ; and, between these two 

 extremes, there are several gradations, the shape and characters of the 

 occipital bone varying in proportion. 



In Man the occipital bone is convex exteriorly, and, sweeping under 

 the cranial cavity, forms the greatest portion of its base ; but in the 

 lower Mammalia, as the Cat, Dog, Horse, &c., it rather forms its poste- 

 rior wall, descending abruptly, and at an acute angle, from its union with 

 the parietal bones, its cuneiform process (anterior to the foramen mag- 

 num) alone, in union with the sphenoid, forming the narrow floor of the 

 cranial cavity, which is not carried back, as in Man and the Simise, beyond 

 the foramen magnum. On each side of this foramen are the condyies, 

 but not precisely on each side of it ; they are more or less anterior to it, 

 obliquely pointing towards each other, so as nearly to touch in front. In 

 Man, who, of all animals, can be said to possess a face (in the restricted 

 sense of the word) in contradistinction to what we term a muzzle, the 

 condyies have a basal situation, and form points, upon which the skull is 

 balanced, having a situation nearly centrical, between the back of the occi- 

 put, and the anterior part of the superior maxillary bone : they constitute 

 the antero-lateral margin of the foramen magnum ; and are elongated, and 

 rise in the middle like a bridge, their posterior end being about the centre 

 of the foramen : but the centre of the foramen magnum is not the exact 

 centre of gravity. In various skulls of the human subject (European), which 

 have been purposely measured, drawing a line, from the alveolar processes 

 of the two middle incisor teeth, to the posterior part of the occiput, this 

 point has been found to vary from half an inch to an inch, and rather more, 

 nearer the occiput than the facial point of measurement.* As, then, the 



* Daubenton says, the human skull is so well placed, as regards equilibrium, that were the vertical 

 line of the body and neck prolonged, "upward, it would pass through the summit of the cranium 

 (Memoires, &c., p. 568): and, in another part of his article, he speaks of the human head as being 

 placed in equilibrio, as on a pivot (p. 570). Cuvier says, the position of the two condyies, upon which 

 the head rests, is such, that they nearly bisect a line drawn from the most projecting part of the occiput 

 to the [incisor teeth : the consequence of this disposition, he adds, is, that, in the vertical attitude, 

 the head is in equilibrio upon the spine (Lemons, &c. i. 225): and, again, the head, in an upright 

 position, is in a state of equilibrium on the trunk, its articulation being strictly centrical in reference 

 to its own bulk. Virey observes, in the white man, and especially in the European, the occipital 

 aperture is directly under the cranium, so that the head is posited in equilibrio on the atlas (Diet, 

 des Sciences Med. vol. xxi. p. 194). Cloquet says, this opening in man looks downward, and is 

 found nearly in the centre of the head (?) which is in equilibrio on the vertebral column (Anat. de 

 I'Homme, vol. i. p. 117): and Abernethy states, "that the condyies are placed so exactly parallel to 

 the centre of gravity, that when we sit upright, and go to sleep in that posture, the weight of the head 

 has a tendency to preponderate equally, in every direction, as we see in those who are dozing in a 

 carriage : nay, their heads sometimes," he adds, " revolve in a circle, like the head of Harlequin on 

 the stage" (Phys. Led. p. 115). Mr. Lawrence, however, insists, that the head is not placed in a state 

 of perfect equilibrium, in the vertical altitude on the spine ; the parts in front of the column not 

 exactly counterbalancing those behind it. " The occipital condyies," he says, "are manifestly nearer 

 to the occipital tuberosity than to the most prominent part of the jaws, and thus the greater share of 

 the weight is in front of the joint. Place the occipital condyies on any point of support, and the head 

 will incline forward, unless it be held in equilibrio by a force applied behind. The preponderance is 

 greater when the lower jaw is added ; and it is still further increased by the accession of the tongue, 



